Urological resectoscope having a non-rotating instrument support

ABSTRACT

A urological resectoscope having a tubular shaft ( 3 ) is disclosed, having a fixed optical guide tube ( 2 ), within which there is an optical system ( 1 ) that projects distally beyond the optical guide tube. An elongate, rod-shaped carrier ( 4 ) is provided, which carries a cutting instrument ( 6 ) at its distal end. The carrier ( 4 ) is longitudinally moveably mounted in the tubular shaft ( 3 ) outside the optical guide tube ( 2 ). The carrier is held distally from the optical guide tube ( 2 ) with a sliding tube ( 8 ) on the optical system ( 1 ) at a radial spacing from the axis of the optical system ( 1 ). The carrier is also secured in the peripheral rotary direction to the optical guide tube ( 2 ) with a rotary lock ( 9, 10 ). The rotary lock has a bar ( 9 ) parallel to the carrier ( 4 ) and connected to it and a distally open elongate slot ( 10 ) in the optical guide tube ( 2 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a urological resectoscope with a tubular shafthaving a fixed optical guide tube, within which there is an opticalsystem.

2. Description of Related Art

Urological resectoscopes, as are disclosed in DE 3603758 A1, areintroduced e.g. through the urethra to the working location, commonlythe prostate. Cutting is effected at that point with reciprocatingmovement of the instrument in the longitudinal direction, which iscontrolled via its carrier by an operating member disposed beyond theproximal end of the tubular shaft. The instrument is generally a cuttingloop to which HF is applied but can also be a knife for specialapplications. Such resectoscopes may also be used for otherapplications, for instance in the gynaecological field.

In order to be able to make precise cuts with the instrument, e.g. thecutting loop, in the field of view in front of the optical system, theinstrument must be reliably guided by means of its carrier with respectto its radial spacing and its angle of rotation whilst ensuring easylongitudinal movability.

The conventional prior art is shown in FIG. 4 of the aforementionedpublication. The carrier is mounted with a sliding tube connected to iton the optical system so as to be longitudinally moveable but at aguaranteed radial spacing, namely on the portion of the optical systemwhich projects distally beyond an optical guide tube connected to theresectoscope and serving to reliably guide and mount it.

The circumferential angular guidance is problematic in thisconstruction. The conventional prior art in this connection isillustrated in FIG. 4 of the aforementioned publication. Connected tothe optical guide tube and parallel to it is a carrier guide tube,through which the carrier longitudinally moveably passes and whichimparts to the carrier the desired rotational location.

Of disadvantage with this conventional prior art is the additionallynecessary carrier guide tube, which is provided parallel on the opticalguide tube and is connected to it, for instance by soldering and resultsin a complex construction of the optical guide tube and which isparticularly difficult to clean by reason of its small diameter, whichis necessary for reliable guidance.

SUMMARY OF THE INVENTION

The object of the present invention resides in structurally improvingthe rotational location in a resectoscope of the type referred to above.

In accordance with the invention, provided on the carrier there is abar, which may be introduced in the sliding direction of the carrierfrom the distal end into the slot in the optical guide tube and theresecures its rotary position about the axis of the optical system whilstensuring the longitudinal movability of the carrier. Together with thesliding tube, which is in any event present, the result is a highlyprecise guidance of the carrier and thus of the instrument. This is avery simple construction, in which only one simple bar is necessary onthe carrier and, on the endoscope, merely one slot in the optical guidetube, which does not impair its characteristics, may be simplymanufactured in the form of a cut out and does not impair the cleaningpossibilities of the resectoscope.

With a single cut, which with modern laser cutting technology can beaccomplished with suitable contour guidance when cutting the opticalguide tube to size, the distal end of the sliding tube can be cut awayin a suitable shape such that it not only forms the sliding tube butalso, in its proximal region, the bar, which will fit extremelyprecisely into the slot remaining in the optical guide tube aftercutting out the bar. This cut away end portion need only be connected tothe carrier in the same manner as the sliding tube is connected in theprior art.

In order to facilitate the introduction of the carrier, the proximal endof the bar can be tapered to a point or of rounded shape and the entryregion of the slot can be broadened in the same manner, e.g. of conicalshape. Thus even if the insertion is effected “blind”, a cleanintroduction is always achieved, even if the angular position is notexact.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is schematically illustrated by way of example in thedrawings, in which:

FIG. 1 is a perspective view of a resectoscope in accordance with theinvention in the distal end region of the optical system, without thetubular shaft, and

FIG. 2 is a side view of FIG. 1, with the tubular shaft.

DETAILED DESCRIPTION OF THE INVENTION

The figures show the distal end region of an optical system 1 and anoptical guide tube 2 of a resectoscope, the remainder of which isomitted for simplification of the drawing and which otherwise can beconstructed e.g. in accordance with FIG. 2 of DE 3603785 A1.

The optical guide tube 2 is connected to a main body, not shown, of theresectoscope, to which the tubular shaft 3, which is shown in chainlines in FIG. 2, is connected, optionally removably.

Extending through the main body is an elongate, rod-shaped carrier 4,which extends within the tubular shaft 3 parallel to the optical system1 and is actuated in the longitudinal direction by a sliding member,which is provided proximally of the main body and is not illustrated.

The carrier 4 extends within the tubular shaft 3 to the distal endregion of the optical system 1 and then branches in the conventionalconstruction to form a fork 5, which carries a cutting loop 6. Thelatter is electrically connected to an HF connector by an electricalconductor, which passes through the externally insulated carrier 4, onthe proximal end of the carrier 4, which is not shown. In anotherconstruction, the carrier 4 can carry a non-electric knife at its end.

Work is performed with reciprocating movement in the longitudinaldirection with the instrument carried by the carrier 4, the cutting loop6 in the exemplary embodiment, whilst viewing though the objective 7provided at the distal end of the optical system 1. In order to ensurereliable working, the cutting loop 6 must be reliably positioned bymeans of the carrier 4, as regards both its radial spacing from the axisof the optical system 1 and in the circumferential rotational angulardirection, with respect to this axis.

For the purpose of radial guidance, connected to the carrier 4 is asliding tube 8, which is longitudinally moveably guided on the region ofthe optical system 1 projecting beyond the distal end of the opticalguide tube 2.

For the purpose of rotational angular location, a bar 9 is connected tothe carrier 4, which engages in a distally open slot 10 in the opticalguide tube 2 to be neatly longitudinally guided.

The sliding tube 8 and bar 9 can be constructed in the form ofcomponents connected separately to the carrier 4. However, in theillustrated embodiment, they are of one-piece construction in the formof a tubular member appropriately cut to size.

As shown in the figures, the component consisting of the sliding tube 8and bar 9 is of tubular construction so that it fits without a gap afterbeing inserted in the proximal direction until it hits an end stop onthe optical guide tube. It can therefore be manufactured in a verysimple manner by cutting the component consisting of the sliding tube 8and bar 9 out of the optical guide tube with a severing cut. A reliablefit is thus ensured.

As may also be seen in the figures, the proximal end of the bar 9 isrounded. The introduction of the bar into the distal end of the slot 10is thus facilitated. Alternatively or additionally, the distal end ofthe slot 10 can be conically broadened towards its end in order tofacilitate introduction.

1. A urological resectoscope with a tubular shaft (3), having a fixedoptical guide tube (2), within which there is an optical system (1),which projects distally beyond the optical guide tube, an elongate,rod-shaped carrier (4), which carries a cutting instrument (6) at itsdistal end, being longitudinally moveably mounted in the tubular shaft(3) outside the optical guide tube (2), which carrier is held distallyfrom the optical guide tube (2) with a sliding tube (8) on the opticalsystem (1) at a radial spacing from the axis of the optical system (1)and is secured in the peripheral rotary direction to the optical guidetube (2) with a rotary lock (9,10), wherein the rotary lock has a bar(9) parallel to the carrier (4) and connected to it and a distally openelongate slot (10) in the optical guide tube (2).
 2. A resectoscope asclaimed in claim 1, wherein the sliding tube (8) is integral with thebar (9) in the form of a cut away distal end piece of the optical guidetube (2).
 3. A resectoscope as claimed in claim 1, wherein the proximalend of the bar (9) and/or the distal end of the slot (10) are sloped.